Saint Ildefonso, a seventh-century archbishop and the patron saint of Toledo, interrupts his writing to gaze devoutly at a statue of the Virgin. In the sixteenth century the saint was accused of heresy by critics outside Spain, and this composition, which includes Ildefonso in the company of Saint Jerome and other divinely inspired scribes, reinforces the saint's authority.

Scintillating colors and flickering white accents amplify Ildefonso's emotional intensity. The nineteenth-century French painter Jean-François Millet, who owned the painting and hung it over his bed, remarked, "you'd need a lot of heart to make a work like that." Millet and later Edgar Degas (who bought Saint Ildefonso from Millet's estate) were largely responsible for the revival of interest in El Greco's art, but their emphasis on his emotion and "modern" technique also clouded understanding of the painter's relation to his period.